Whether listening to an MP3 player while traveling, or to a high-fidelity stereo system at home, consumers are increasingly choosing intra-canal and intra-concha earphones for their listening pleasure. Both types of electro-acoustic transducer devices have a relatively low profile housing that contains a receiver or driver (an earpiece speaker). The low profile housing provides convenience for the wearer, while also providing very good sound quality.
Intra-canal earphones are typically designed to fit within and form a seal with the user's ear canal. Intra-canal earphones therefore have an acoustic output tube portion that extends from the housing. The open end of the acoustic output tube portion can be inserted into the wearer's ear canal. The acoustic output tube portion typically forms, or is fitted with, a flexible and resilient tip or cap made of a rubber or silicone material. The tip may be custom molded for the discerning audiophile, or it may be a high volume manufactured piece. When the tip portion is inserted into the user's ear, the tip compresses against the ear canal wall and creates a sealed (essentially airtight) cavity inside the canal. Although the sealed cavity allows for maximum sound output power into the ear canal, it can amplify external vibrations, thus diminishing overall sound quality.
Intra-concha earphones, on the other hand, typically fit in the outer ear and rest just above the inner ear canal. Intra-concha earphones do not typically seal within the ear canal and therefore do not suffer from the same issues as intra-canal earphones. Sound quality, however, may not be optimal to the user because sound can leak from the earphone and not reach the ear canal. In addition, due to the differences in ear shapes and sizes, different amounts of sound may leak thus resulting in inconsistent acoustic performance between users.